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2022-09-26nfsd: use DEFINE_SHOW_ATTRIBUTE to define nfsd_reply_cache_stats_fopsChenXiaoSong1-10/+3
Use DEFINE_SHOW_ATTRIBUTE helper macro to simplify the code. nfsd_net is converted from seq_file->file instead of seq_file->private in nfsd_reply_cache_stats_show(). Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com> [ cel: reduce line length ] Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-07-03mm: shrinkers: provide shrinkers with namesRoman Gushchin1-1/+2
Currently shrinkers are anonymous objects. For debugging purposes they can be identified by count/scan function names, but it's not always useful: e.g. for superblock's shrinkers it's nice to have at least an idea of to which superblock the shrinker belongs. This commit adds names to shrinkers. register_shrinker() and prealloc_shrinker() functions are extended to take a format and arguments to master a name. In some cases it's not possible to determine a good name at the time when a shrinker is allocated. For such cases shrinker_debugfs_rename() is provided. The expected format is: <subsystem>-<shrinker_type>[:<instance>]-<id> For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair. After this change the shrinker debugfs directory looks like: $ cd /sys/kernel/debug/shrinker/ $ ls dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42 mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43 mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44 rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49 sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13 sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36 sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19 sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10 sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9 sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37 sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38 sb-dax-11 sb-proc-45 sb-tmpfs-35 sb-debugfs-7 sb-proc-46 sb-tmpfs-40 [roman.gushchin@linux.dev: fix build warnings] Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle Reported-by: kernel test robot <lkp@intel.com> Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-23nfsd: destroy percpu stats counters after reply cache shutdownJulian Schroeder1-1/+1
Upon nfsd shutdown any pending DRC cache is freed. DRC cache use is tracked via a percpu counter. In the current code the percpu counter is destroyed before. If any pending cache is still present, percpu_counter_add is called with a percpu counter==NULL. This causes a kernel crash. The solution is to destroy the percpu counter after the cache is freed. Fixes: e567b98ce9a4b (“nfsd: protect concurrent access to nfsd stats counters”) Signed-off-by: Julian Schroeder <jumaco@amazon.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-02-28NFSD: Streamline the rare "found" caseChuck Lever1-4/+3
Move a rarely called function call site out of the hot path. This is an exceptionally small improvement because the compiler inlines most of the functions that nfsd_cache_lookup() calls. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-02-28NFSD: Skip extra computation for RC_NOCACHE caseChuck Lever1-2/+4
Force the compiler to skip unneeded initialization for cases that don't need those values. For example, NFSv4 COMPOUND operations are RC_NOCACHE. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-02-28NFSD: De-duplicate hash bucket indexingChuck Lever1-12/+10
Clean up: The details of finding the right hash bucket are exactly the same in both nfsd_cache_lookup() and nfsd_cache_update(). Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: Remove be32_to_cpu() from DRC hash functionChuck Lever1-1/+1
Commit 7142b98d9fd7 ("nfsd: Clean up drc cache in preparation for global spinlock elimination"), billed as a clean-up, added be32_to_cpu() to the DRC hash function without explanation. That commit removed two comments that state that byte-swapping in the hash function is unnecessary without explaining whether there was a need for that change. On some Intel CPUs, the swab32 instruction is known to cause a CPU pipeline stall. be32_to_cpu() does not add extra randomness, since the hash multiplication is done /before/ shifting to the high-order bits of the result. As a micro-optimization, remove the unnecessary transform from the DRC hash function. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-09-21NFSD: Optimize DRC bucket pruningChuck Lever1-6/+11
DRC bucket pruning is done by nfsd_cache_lookup(), which is part of every NFSv2 and NFSv3 dispatch (ie, it's done while the client is waiting). I added a trace_printk() in prune_bucket() to see just how long it takes to prune. Here are two ends of the spectrum: prune_bucket: Scanned 1 and freed 0 in 90 ns, 62 entries remaining prune_bucket: Scanned 2 and freed 1 in 716 ns, 63 entries remaining ... prune_bucket: Scanned 75 and freed 74 in 34149 ns, 1 entries remaining Pruning latency is noticeable on fast transports with fast storage. By noticeable, I mean that the latency measured here in the worst case is the same order of magnitude as the round trip time for cached server operations. We could do something like moving expired entries to an expired list and then free them later instead of freeing them right in prune_bucket(). But simply limiting the number of entries that can be pruned by a lookup is simple and retains more entries in the cache, making the DRC somewhat more effective. Comparison with a 70/30 fio 8KB 12 thread direct I/O test: Before: write: IOPS=61.6k, BW=481MiB/s (505MB/s)(14.1GiB/30001msec); 0 zone resets WRITE: 1848726 ops (30%) avg bytes sent per op: 8340 avg bytes received per op: 136 backlog wait: 0.635158 RTT: 0.128525 total execute time: 0.827242 (milliseconds) After: write: IOPS=63.0k, BW=492MiB/s (516MB/s)(14.4GiB/30001msec); 0 zone resets WRITE: 1891144 ops (30%) avg bytes sent per op: 8340 avg bytes received per op: 136 backlog wait: 0.616114 RTT: 0.126842 total execute time: 0.805348 (milliseconds) Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-01-25nfsd: protect concurrent access to nfsd stats countersAmir Goldstein1-15/+37
nfsd stats counters can be updated by concurrent nfsd threads without any protection. Convert some nfsd_stats and nfsd_net struct members to use percpu counters. The longest_chain* members of struct nfsd_net remain unprotected. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2020-09-25silence nfscache allocation warnings with kvzallocRik van Riel1-8/+4
silence nfscache allocation warnings with kvzalloc Currently nfsd_reply_cache_init attempts hash table allocation through kmalloc, and manually falls back to vzalloc if that fails. This makes the code a little larger than needed, and creates a significant amount of serial console spam if you have enough systems. Switching to kvzalloc gets rid of the allocation warnings, and makes the code a little cleaner too as a side effect. Freeing of nn->drc_hashtbl is already done using kvfree currently. Signed-off-by: Rik van Riel <riel@surriel.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-06-03nfsd: safer handling of corrupted c_typeJ. Bruce Fields1-2/+1
This can only happen if there's a bug somewhere, so let's make it a WARN not a printk. Also, I think it's safest to ignore the corruption rather than trying to fix it by removing a cache entry. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-06-01nfsd4: make drc_slab global, not per-netJ. Bruce Fields1-12/+17
I made every global per-network-namespace instead. But perhaps doing that to this slab was a step too far. The kmem_cache_create call in our net init method also seems to be responsible for this lockdep warning: [ 45.163710] Unable to find swap-space signature [ 45.375718] trinity-c1 (855): attempted to duplicate a private mapping with mremap. This is not supported. [ 46.055744] futex_wake_op: trinity-c1 tries to shift op by -209; fix this program [ 51.011723] [ 51.013378] ====================================================== [ 51.013875] WARNING: possible circular locking dependency detected [ 51.014378] 5.2.0-rc2 #1 Not tainted [ 51.014672] ------------------------------------------------------ [ 51.015182] trinity-c2/886 is trying to acquire lock: [ 51.015593] 000000005405f099 (slab_mutex){+.+.}, at: slab_attr_store+0xa2/0x130 [ 51.016190] [ 51.016190] but task is already holding lock: [ 51.016652] 00000000ac662005 (kn->count#43){++++}, at: kernfs_fop_write+0x286/0x500 [ 51.017266] [ 51.017266] which lock already depends on the new lock. [ 51.017266] [ 51.017909] [ 51.017909] the existing dependency chain (in reverse order) is: [ 51.018497] [ 51.018497] -> #1 (kn->count#43){++++}: [ 51.018956] __lock_acquire+0x7cf/0x1a20 [ 51.019317] lock_acquire+0x17d/0x390 [ 51.019658] __kernfs_remove+0x892/0xae0 [ 51.020020] kernfs_remove_by_name_ns+0x78/0x110 [ 51.020435] sysfs_remove_link+0x55/0xb0 [ 51.020832] sysfs_slab_add+0xc1/0x3e0 [ 51.021332] __kmem_cache_create+0x155/0x200 [ 51.021720] create_cache+0xf5/0x320 [ 51.022054] kmem_cache_create_usercopy+0x179/0x320 [ 51.022486] kmem_cache_create+0x1a/0x30 [ 51.022867] nfsd_reply_cache_init+0x278/0x560 [ 51.023266] nfsd_init_net+0x20f/0x5e0 [ 51.023623] ops_init+0xcb/0x4b0 [ 51.023928] setup_net+0x2fe/0x670 [ 51.024315] copy_net_ns+0x30a/0x3f0 [ 51.024653] create_new_namespaces+0x3c5/0x820 [ 51.025257] unshare_nsproxy_namespaces+0xd1/0x240 [ 51.025881] ksys_unshare+0x506/0x9c0 [ 51.026381] __x64_sys_unshare+0x3a/0x50 [ 51.026937] do_syscall_64+0x110/0x10b0 [ 51.027509] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 51.028175] [ 51.028175] -> #0 (slab_mutex){+.+.}: [ 51.028817] validate_chain+0x1c51/0x2cc0 [ 51.029422] __lock_acquire+0x7cf/0x1a20 [ 51.029947] lock_acquire+0x17d/0x390 [ 51.030438] __mutex_lock+0x100/0xfa0 [ 51.030995] mutex_lock_nested+0x27/0x30 [ 51.031516] slab_attr_store+0xa2/0x130 [ 51.032020] sysfs_kf_write+0x11d/0x180 [ 51.032529] kernfs_fop_write+0x32a/0x500 [ 51.033056] do_loop_readv_writev+0x21d/0x310 [ 51.033627] do_iter_write+0x2e5/0x380 [ 51.034148] vfs_writev+0x170/0x310 [ 51.034616] do_pwritev+0x13e/0x160 [ 51.035100] __x64_sys_pwritev+0xa3/0x110 [ 51.035633] do_syscall_64+0x110/0x10b0 [ 51.036200] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 51.036924] [ 51.036924] other info that might help us debug this: [ 51.036924] [ 51.037876] Possible unsafe locking scenario: [ 51.037876] [ 51.038556] CPU0 CPU1 [ 51.039130] ---- ---- [ 51.039676] lock(kn->count#43); [ 51.040084] lock(slab_mutex); [ 51.040597] lock(kn->count#43); [ 51.041062] lock(slab_mutex); [ 51.041320] [ 51.041320] *** DEADLOCK *** [ 51.041320] [ 51.041793] 3 locks held by trinity-c2/886: [ 51.042128] #0: 000000001f55e152 (sb_writers#5){.+.+}, at: vfs_writev+0x2b9/0x310 [ 51.042739] #1: 00000000c7d6c034 (&of->mutex){+.+.}, at: kernfs_fop_write+0x25b/0x500 [ 51.043400] #2: 00000000ac662005 (kn->count#43){++++}, at: kernfs_fop_write+0x286/0x500 Reported-by: kernel test robot <lkp@intel.com> Fixes: 3ba75830ce17 "drc containerization" Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-05-20NFSD: Add tracepoints to NFSD's duplicate reply cacheChuck Lever1-22/+35
Try to capture DRC failures. Two additional clean-ups: - Introduce Doxygen-style comments for the main entry points - Remove a dprintk that fires for an allocation failure. This was the only dprintk in the REPCACHE class. Reported-by: kbuild test robot <lkp@intel.com> [ cel: force typecast for display of checksum values ] Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2019-08-16nfsd4: Fix kernel crash when reading proc file reply_cache_statsHe Zhe1-1/+1
reply_cache_stats uses wrong parameter as seq file private structure and thus causes the following kernel crash when users read /proc/fs/nfsd/reply_cache_stats BUG: kernel NULL pointer dereference, address: 00000000000001f9 PGD 0 P4D 0 Oops: 0000 [#3] SMP PTI CPU: 6 PID: 1502 Comm: cat Tainted: G D 5.3.0-rc3+ #1 Hardware name: Intel Corporation Broadwell Client platform/Basking Ridge, BIOS BDW-E2R1.86C.0118.R01.1503110618 03/11/2015 RIP: 0010:nfsd_reply_cache_stats_show+0x3b/0x2d0 Code: 41 54 49 89 f4 48 89 fe 48 c7 c7 b3 10 33 88 53 bb e8 03 00 00 e8 88 82 d1 ff bf 58 89 41 00 e8 eb c5 85 00 48 83 eb 01 75 f0 <41> 8b 94 24 f8 01 00 00 48 c7 c6 be 10 33 88 4c 89 ef bb e8 03 00 RSP: 0018:ffffaa520106fe08 EFLAGS: 00010246 RAX: 000000cfe1a77123 RBX: 0000000000000000 RCX: 0000000000291b46 RDX: 000000cf00000000 RSI: 0000000000000006 RDI: 0000000000291b28 RBP: ffffaa520106fe20 R08: 0000000000000006 R09: 000000cfe17e55dd R10: ffffa424e47c0000 R11: 000000000000030b R12: 0000000000000001 R13: ffffa424e5697000 R14: 0000000000000001 R15: ffffa424e5697000 FS: 00007f805735f580(0000) GS:ffffa424f8f80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000001f9 CR3: 00000000655ce005 CR4: 00000000003606e0 Call Trace: seq_read+0x194/0x3e0 __vfs_read+0x1b/0x40 vfs_read+0x95/0x140 ksys_read+0x61/0xe0 __x64_sys_read+0x1a/0x20 do_syscall_64+0x4d/0x120 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f805728b861 Code: fe ff ff 50 48 8d 3d 86 b4 09 00 e8 79 e0 01 00 66 0f 1f 84 00 00 00 00 00 48 8d 05 d9 19 0d 00 8b 00 85 c0 75 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 57 c3 66 0f 1f 44 00 00 48 83 ec 28 48 89 54 RSP: 002b:00007ffea1ce3c38 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f805728b861 RDX: 0000000000020000 RSI: 00007f8057183000 RDI: 0000000000000003 RBP: 00007f8057183000 R08: 00007f8057182010 R09: 0000000000000000 R10: 0000000000000022 R11: 0000000000000246 R12: 0000559a60e8ff10 R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000 Modules linked in: CR2: 00000000000001f9 ---[ end trace 01613595153f0cba ]--- RIP: 0010:nfsd_reply_cache_stats_show+0x3b/0x2d0 Code: 41 54 49 89 f4 48 89 fe 48 c7 c7 b3 10 33 88 53 bb e8 03 00 00 e8 88 82 d1 ff bf 58 89 41 00 e8 eb c5 85 00 48 83 eb 01 75 f0 <41> 8b 94 24 f8 01 00 00 48 c7 c6 be 10 33 88 4c 89 ef bb e8 03 00 RSP: 0018:ffffaa52004b3e08 EFLAGS: 00010246 RAX: 0000002bab45a7c6 RBX: 0000000000000000 RCX: 0000000000291b4c RDX: 0000002b00000000 RSI: 0000000000000004 RDI: 0000000000291b28 RBP: ffffaa52004b3e20 R08: 0000000000000004 R09: 0000002bab1c8c7a R10: ffffa424e5500000 R11: 00000000000002a9 R12: 0000000000000001 R13: ffffa424e4475000 R14: 0000000000000001 R15: ffffa424e4475000 FS: 00007f805735f580(0000) GS:ffffa424f8f80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000001f9 CR3: 00000000655ce005 CR4: 00000000003606e0 Killed Fixes: 3ba75830ce17 ("nfsd4: drc containerization") Signed-off-by: He Zhe <zhe.he@windriver.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-07-03nfsd: fix cleanup of nfsd_reply_cache_init on failureJ. Bruce Fields1-3/+7
The failure to unregister the shrinker results will result in corruption when the nfsd_net is freed. Also clean up the drc_slab while we're here. Reported-by: syzbot+83a43746cebef3508b49@syzkaller.appspotmail.com Fixes: db17b61765c2 ("nfsd4: drc containerization") Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-07-03nfsd4: drc containerizationJ. Bruce Fields1-117/+108
The nfsd duplicate reply cache should not be shared between network namespaces. The most straightforward way to fix this is just to move every global in the code to per-net-namespace memory, so that's what we do. Still todo: sort out which members of nfsd_stats should be global and which per-net-namespace. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-07-03nfsd: don't call nfsd_reply_cache_shutdown twiceJ. Bruce Fields1-1/+0
The caller is cleaning up on ENOMEM, don't try to do it here too. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-12-28mm: convert totalram_pages and totalhigh_pages variables to atomicArun KS1-1/+1
totalram_pages and totalhigh_pages are made static inline function. Main motivation was that managed_page_count_lock handling was complicating things. It was discussed in length here, https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes better to remove the lock and convert variables to atomic, with preventing poteintial store-to-read tearing as a bonus. [akpm@linux-foundation.org: coding style fixes] Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS <arunks@codeaurora.org> Suggested-by: Michal Hocko <mhocko@suse.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-29knfsd: Improve lookup performance in the duplicate reply cache using an rbtreeTrond Myklebust1-11/+26
Use an rbtree to ensure the lookup/insert of an entry in a DRC bucket is O(log(N)). Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-10-29knfsd: Further simplify the cache lookupTrond Myklebust1-29/+16
Order the structure so that the key can be compared using memcmp(). Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-10-29knfsd: Simplify NFS duplicate replay cacheTrond Myklebust1-50/+44
Simplify the duplicate replay cache by initialising the preallocated cache entry, so that we can use it as a key for the cache lookup. Note that the 99.999% case we want to optimise for is still the one where the lookup fails, and we have to add this entry to the cache, so preinitialising should not cause a performance penalty. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-10-29knfsd: Remove dead code from nfsd_cache_lookupTrond Myklebust1-8/+0
The preallocated cache entry is always set to type RC_NOCACHE, and that type isn't changed until we later call nfsd_cache_update(). Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-06-12Merge tag 'overflow-v4.18-rc1-part2' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull more overflow updates from Kees Cook: "The rest of the overflow changes for v4.18-rc1. This includes the explicit overflow fixes from Silvio, further struct_size() conversions from Matthew, and a bug fix from Dan. But the bulk of it is the treewide conversions to use either the 2-factor argument allocators (e.g. kmalloc(a * b, ...) into kmalloc_array(a, b, ...) or the array_size() macros (e.g. vmalloc(a * b) into vmalloc(array_size(a, b)). Coccinelle was fighting me on several fronts, so I've done a bunch of manual whitespace updates in the patches as well. Summary: - Error path bug fix for overflow tests (Dan) - Additional struct_size() conversions (Matthew, Kees) - Explicitly reported overflow fixes (Silvio, Kees) - Add missing kvcalloc() function (Kees) - Treewide conversions of allocators to use either 2-factor argument variant when available, or array_size() and array3_size() as needed (Kees)" * tag 'overflow-v4.18-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (26 commits) treewide: Use array_size in f2fs_kvzalloc() treewide: Use array_size() in f2fs_kzalloc() treewide: Use array_size() in f2fs_kmalloc() treewide: Use array_size() in sock_kmalloc() treewide: Use array_size() in kvzalloc_node() treewide: Use array_size() in vzalloc_node() treewide: Use array_size() in vzalloc() treewide: Use array_size() in vmalloc() treewide: devm_kzalloc() -> devm_kcalloc() treewide: devm_kmalloc() -> devm_kmalloc_array() treewide: kvzalloc() -> kvcalloc() treewide: kvmalloc() -> kvmalloc_array() treewide: kzalloc_node() -> kcalloc_node() treewide: kzalloc() -> kcalloc() treewide: kmalloc() -> kmalloc_array() mm: Introduce kvcalloc() video: uvesafb: Fix integer overflow in allocation UBIFS: Fix potential integer overflow in allocation leds: Use struct_size() in allocation Convert intel uncore to struct_size ...
2018-06-12treewide: Use array_size() in vzalloc()Kees Cook1-1/+2
The vzalloc() function has no 2-factor argument form, so multiplication factors need to be wrapped in array_size(). This patch replaces cases of: vzalloc(a * b) with: vzalloc(array_size(a, b)) as well as handling cases of: vzalloc(a * b * c) with: vzalloc(array3_size(a, b, c)) This does, however, attempt to ignore constant size factors like: vzalloc(4 * 1024) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( vzalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | vzalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( vzalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | vzalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | vzalloc( - sizeof(char) * (COUNT) + COUNT , ...) | vzalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | vzalloc( - sizeof(u8) * COUNT + COUNT , ...) | vzalloc( - sizeof(__u8) * COUNT + COUNT , ...) | vzalloc( - sizeof(char) * COUNT + COUNT , ...) | vzalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( vzalloc( - sizeof(TYPE) * (COUNT_ID) + array_size(COUNT_ID, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * COUNT_ID + array_size(COUNT_ID, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * (COUNT_CONST) + array_size(COUNT_CONST, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * COUNT_CONST + array_size(COUNT_CONST, sizeof(TYPE)) , ...) | vzalloc( - sizeof(THING) * (COUNT_ID) + array_size(COUNT_ID, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * COUNT_ID + array_size(COUNT_ID, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * (COUNT_CONST) + array_size(COUNT_CONST, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * COUNT_CONST + array_size(COUNT_CONST, sizeof(THING)) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ vzalloc( - SIZE * COUNT + array_size(COUNT, SIZE) , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( vzalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vzalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( vzalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | vzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | vzalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | vzalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | vzalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | vzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( vzalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( vzalloc(C1 * C2 * C3, ...) | vzalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants. @@ expression E1, E2; constant C1, C2; @@ ( vzalloc(C1 * C2, ...) | vzalloc( - E1 * E2 + array_size(E1, E2) , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-05-11nfsd: Do not refuse to serve out of cacheTrond Myklebust1-4/+2
Currently the knfsd replay cache appears to try to refuse replying to retries that come within 200ms of the cache entry being created. That makes limited sense in today's world of high speed TCP. After a TCP disconnection, a client can very easily reconnect and retry an rpc in less than 200ms. If this logic drops that retry, however, the client may be quite slow to retry again. This logic is original to the first reply cache implementation in 2.1, and may have made more sense for UDP clients that retried much more frequently. After this patch we will still drop on finding the original request still in progress. We may want to fix that as well at some point, though it's less likely. Note that svc_check_conn_limits is often the cause of those disconnections. We may want to fix that some day. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Acked-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-27lib/vsprintf.c: remove %Z supportAlexey Dobriyan1-1/+1
Now that %z is standartised in C99 there is no reason to support %Z. Unlike %L it doesn't even make format strings smaller. Use BUILD_BUG_ON in a couple ATM drivers. In case anyone didn't notice lib/vsprintf.o is about half of SLUB which is in my opinion is quite an achievement. Hopefully this patch inspires someone else to trim vsprintf.c more. Link: http://lkml.kernel.org/r/20170103230126.GA30170@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-01nfsd: more robust allocation failure handling in nfsd_reply_cache_initJeff Layton1-3/+8
Currently, we try to allocate the cache as a single, large chunk, which can fail if no big chunks of memory are available. We _do_ try to size it according to the amount of memory in the box, but if the server is started well after boot time, then the allocation can fail due to memory fragmentation. Fall back to doing a vzalloc if the kcalloc fails, and switch the shutdown code to do a kvfree to handle freeing correctly. Reported-by: Olaf Hering <olaf@aepfle.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-11-10nfsd: remove recurring workqueue job to clean DRCJeff Layton1-26/+0
We have a shrinker, we clean out the cache when nfsd is shut down, and prune the chains on each request. A recurring workqueue job seems like unnecessary overhead. Just remove it. Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-10-12nfsd: drop null test before destroy functionsJulia Lawall1-4/+2
Remove unneeded NULL test. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression x; @@ -if (x != NULL) { \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x); x = NULL; -} // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-03-20NFSD: Error out when register_shrinker() failKinglong Mee1-1/+5
If register_shrinker() failed, nfsd will cause a NULL pointer access as, [ 9250.875465] nfsd: last server has exited, flushing export cache [ 9251.427270] BUG: unable to handle kernel NULL pointer dereference at (null) [ 9251.427393] IP: [<ffffffff8136fc29>] __list_del_entry+0x29/0xd0 [ 9251.427579] PGD 13e4d067 PUD 13e4c067 PMD 0 [ 9251.427633] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC [ 9251.427706] Modules linked in: ip6t_rpfilter ip6t_REJECT bnep bluetooth xt_conntrack cfg80211 rfkill ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw btrfs xfs microcode ppdev serio_raw pcspkr xor libcrc32c raid6_pq e1000 parport_pc parport i2c_piix4 i2c_core nfsd(OE-) auth_rpcgss nfs_acl lockd sunrpc(E) ata_generic pata_acpi [ 9251.428240] CPU: 0 PID: 1557 Comm: rmmod Tainted: G OE 3.16.0-rc2+ #22 [ 9251.428366] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013 [ 9251.428496] task: ffff880000849540 ti: ffff8800136f4000 task.ti: ffff8800136f4000 [ 9251.428593] RIP: 0010:[<ffffffff8136fc29>] [<ffffffff8136fc29>] __list_del_entry+0x29/0xd0 [ 9251.428696] RSP: 0018:ffff8800136f7ea0 EFLAGS: 00010207 [ 9251.428751] RAX: 0000000000000000 RBX: ffffffffa0116d48 RCX: dead000000200200 [ 9251.428814] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffa0116d48 [ 9251.428876] RBP: ffff8800136f7ea0 R08: ffff8800136f4000 R09: 0000000000000001 [ 9251.428939] R10: 8080808080808080 R11: 0000000000000000 R12: ffffffffa011a5a0 [ 9251.429002] R13: 0000000000000800 R14: 0000000000000000 R15: 00000000018ac090 [ 9251.429064] FS: 00007fb9acef0740(0000) GS:ffff88003fa00000(0000) knlGS:0000000000000000 [ 9251.429164] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 9251.429221] CR2: 0000000000000000 CR3: 0000000031a17000 CR4: 00000000001407f0 [ 9251.429306] Stack: [ 9251.429410] ffff8800136f7eb8 ffffffff8136fcdd ffffffffa0116d20 ffff8800136f7ed0 [ 9251.429511] ffffffff8118a0f2 0000000000000000 ffff8800136f7ee0 ffffffffa00eb765 [ 9251.429610] ffff8800136f7ef0 ffffffffa010e93c ffff8800136f7f78 ffffffff81104ac2 [ 9251.429709] Call Trace: [ 9251.429755] [<ffffffff8136fcdd>] list_del+0xd/0x30 [ 9251.429896] [<ffffffff8118a0f2>] unregister_shrinker+0x22/0x40 [ 9251.430037] [<ffffffffa00eb765>] nfsd_reply_cache_shutdown+0x15/0x90 [nfsd] [ 9251.430106] [<ffffffffa010e93c>] exit_nfsd+0x9/0x6cd [nfsd] [ 9251.430192] [<ffffffff81104ac2>] SyS_delete_module+0x162/0x200 [ 9251.430280] [<ffffffff81013b69>] ? do_notify_resume+0x59/0x90 [ 9251.430395] [<ffffffff816f2369>] system_call_fastpath+0x16/0x1b [ 9251.430457] Code: 00 00 55 48 8b 17 48 b9 00 01 10 00 00 00 ad de 48 8b 47 08 48 89 e5 48 39 ca 74 29 48 b9 00 02 20 00 00 00 ad de 48 39 c8 74 7a <4c> 8b 00 4c 39 c7 75 53 4c 8b 42 08 4c 39 c7 75 2b 48 89 42 08 [ 9251.430691] RIP [<ffffffff8136fc29>] __list_del_entry+0x29/0xd0 [ 9251.430755] RSP <ffff8800136f7ea0> [ 9251.430805] CR2: 0000000000000000 [ 9251.431033] ---[ end trace 080f3050d082b4ea ]--- Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-12-09sunrpc: add a generic rq_flags field to svc_rqst and move rq_secure to itJeff Layton1-2/+2
In a later patch, we're going to need some atomic bit flags. Since that field will need to be an unsigned long, we mitigate that space consumption by migrating some other bitflags to the new field. Start with the rq_secure flag. Signed-off-by: Jeff Layton <jlayton@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-08-17nfsd: Reorder nfsd_cache_match to check more powerful discriminators firstTrond Myklebust1-7/+11
We would normally expect the xid and the checksum to be the best discriminators. Check them before looking at the procedure number, etc. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-08-17nfsd: split DRC global spinlock into per-bucket locksTrond Myklebust1-23/+20
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-08-17nfsd: convert num_drc_entries to an atomic_tTrond Myklebust1-16/+12
...so we can remove the spinlocking around it. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-08-17nfsd: Remove the cache_hash listTrond Myklebust1-17/+2
Now that the lru list is per-bucket, we don't need a second list for searches. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-08-17nfsd: convert the lru list into a per-bucket thingTrond Myklebust1-23/+50
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-08-17nfsd: Clean up drc cache in preparation for global spinlock eliminationTrond Myklebust1-21/+24
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-06-23nfsd: clean up sparse endianness warnings in nfscache.cJeff Layton1-2/+11
We currently hash the XID to determine a hash bucket to use for the reply cache entry, which is fed into hash_32 without byte-swapping it. Add __force to make sparse happy, and add some comments to explain why. Signed-off-by: Jeff Layton <jlayton@primarydata.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-06-06nfsd: don't halt scanning the DRC LRU list when there's an RC_INPROG entryJeff Layton1-9/+8
Currently, the DRC cache pruner will stop scanning the list when it hits an entry that is RC_INPROG. It's possible however for a call to take a *very* long time. In that case, we don't want it to block other entries from being pruned if they are expired or we need to trim the cache to get back under the limit. Fix the DRC cache pruner to just ignore RC_INPROG entries. Signed-off-by: Jeff Layton <jlayton@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-12-11nfsd: don't try to reuse an expired DRC entry off the listJeff Layton1-32/+4
Currently when we are processing a request, we try to scrape an expired or over-limit entry off the list in preference to allocating a new one from the slab. This is unnecessarily complicated. Just use the slab layer. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-12-10nfsd: when reusing an existing repcache entry, unhash it firstJeff Layton1-1/+8
The DRC code will attempt to reuse an existing, expired cache entry in preference to allocating a new one. It'll then search the cache, and if it gets a hit it'll then free the cache entry that it was going to reuse. The cache code doesn't unhash the entry that it's going to reuse however, so it's possible for it end up designating an entry for reuse and then subsequently freeing the same entry after it finds it. This leads it to a later use-after-free situation and usually some list corruption warnings or an oops. Fix this by simply unhashing the entry that we intend to reuse. That will mean that it's not findable via a search and should prevent this situation from occurring. Cc: stable@vger.kernel.org # v3.10+ Reported-by: Christoph Hellwig <hch@infradead.org> Reported-by: g. artim <gartim@gmail.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-09-10fs: convert fs shrinkers to new scan/count APIDave Chinner1-9/+23
Convert the filesystem shrinkers to use the new API, and standardise some of the behaviours of the shrinkers at the same time. For example, nr_to_scan means the number of objects to scan, not the number of objects to free. I refactored the CIFS idmap shrinker a little - it really needs to be broken up into a shrinker per tree and keep an item count with the tree root so that we don't need to walk the tree every time the shrinker needs to count the number of objects in the tree (i.e. all the time under memory pressure). [glommer@openvz.org: fixes for ext4, ubifs, nfs, cifs and glock. Fixes are needed mainly due to new code merged in the tree] [assorted fixes folded in] Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Glauber Costa <glommer@openvz.org> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Acked-by: Jan Kara <jack@suse.cz> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Cc: Arve Hjønnevåg <arve@android.com> Cc: Carlos Maiolino <cmaiolino@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Rientjes <rientjes@google.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Greg Thelen <gthelen@google.com> Cc: J. Bruce Fields <bfields@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Kent Overstreet <koverstreet@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Thomas Hellstrom <thellstrom@vmware.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-30nfsd: make symbol nfsd_reply_cache_shrinker staticWei Yongjun1-1/+1
symbol 'nfsd_reply_cache_shrinker' only used within this file. It should be static. Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: scale up the number of DRC hash buckets with cache sizeJeff Layton1-15/+29
We've now increased the size of the duplicate reply cache by quite a bit, but the number of hash buckets has not changed. So, we've gone from an average hash chain length of 16 in the old code to 4096 when the cache is its largest. Change the code to scale out the number of buckets with the max size of the cache. At the same time, we also need to fix the hash function since the existing one isn't really suitable when there are more than 256 buckets. Move instead to use the stock hash_32 function for this. Testing on a machine that had 2048 buckets showed that this gave a smaller longest:average ratio than the existing hash function: The formula here is longest hash bucket searched divided by average number of entries per bucket at the time that we saw that longest bucket: old hash: 68/(39258/2048) == 3.547404 hash_32: 45/(33773/2048) == 2.728807 Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: keep stats on worst hash balancing seen so farJeff Layton1-4/+27
The typical case with the DRC is a cache miss, so if we keep track of the max number of entries that we've ever walked over in a search, then we should have a reasonable estimate of the longest hash chain that we've ever seen. With that, we'll also keep track of the total size of the cache when we see the longest chain. In the case of a tie, we prefer to track the smallest total cache size in order to properly gauge the worst-case ratio of max vs. avg chain length. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: add new reply_cache_stats file in nfsdfsJeff Layton1-0/+25
For presenting statistics relating to duplicate reply cache. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: track memory utilization by the DRCJeff Layton1-5/+17
Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: break out comparator into separate functionJeff Layton1-11/+35
Break out the function that compares the rqstp and checksum against a reply cache entry. While we're at it, track the efficacy of the checksum over the NFS data by tracking the cases where we would have incorrectly matched a DRC entry if we had not tracked it or the length. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: eliminate one of the DRC cache searchesJeff Layton1-22/+19
The most common case is to do a search of the cache, followed by an insert. In the case where we have to allocate an entry off the slab, then we end up having to redo the search, which is wasteful. Better optimize the code for the common case by eliminating the initial search of the cache and always preallocating an entry. In the case of a cache hit, we'll end up just freeing that entry but that's preferable to an extra search. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
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